Conventionally, there is known an image-recording apparatus that includes a plurality of liquid chambers in communication with one another. For example, Japanese Patent Application Publication No. 2015-199261 discloses an image-recording apparatus including a plurality of liquid chambers each partitioned into an upper chamber and a lower chamber by a partitioning wall. The upper and lower chambers of each liquid chamber are communicable with each other. The plurality of liquid chambers is made to communicate with the atmosphere through a common single air communication port. This image-recording apparatus also includes a head provided with nozzles through which liquid supplied from the liquid chambers is configured to be ejected.
In this image-recording apparatus, the lower chamber of each liquid chamber is directly in communication with the head including nozzles, while the upper chamber of each liquid chamber is not directly in communication with the head. In this configuration, in order to ensure reliable circulation of liquid, preferably, liquid stored in the upper chamber be used up before liquid stored in the lower chamber is used up. However, since the plurality of liquid chambers is made to communicate with the atmosphere through the common single air communication port, it is structurally difficult to allow liquid stored in one of the chambers to be used up earlier than the liquid stored in another chamber. Also, in this configuration, liquid supply to the head may be interrupted if the single air communication port becomes clogged or blocked for some reason.
Further, generally, the orientation of the image-recording apparatus may be changed during transportation. For example, while the image-recording apparatus should be used with its lower surface placed on a level surface to serve as a bottom of the image-recording apparatus (operable posture), the image-recording apparatus may be put in a vertical orientation with its left surface in the operable posture placed on the level surface to serve as the bottom of the image-recording apparatus (left-surface-down posture); or, with its rear surface in the operable posture placed on the level surface to serve as the bottom of the image-recording apparatus (rear-surface-down posture). If the image-recording apparatus is disposed in such unintended orientation, the head may be positioned below the liquid chambers, which may cause outflow of the liquid from the liquid chamber to the head that directly communicates with the liquid chamber, possibly resulting in leakage of liquid from the head.
In order to prevent such leakage of the liquid, in the above-mentioned image-recording apparatus, a liquid outlet port for discharging the liquid in the liquid chamber to the head is arranged to be positioned upward relative to a liquid level of the liquid within the liquid chamber even if the orientation of the image-recording apparatus is changed.